"We always thought Heidi was bright because she was reading early. I was curious about her IQ and the results were off the scale," the Daily Mail quoted Dr Hankins as saying.

"I got her the complete set of the Oxford Reading Tree books when she was two and she read through the whole set of 30 in about an hour. It's what you would expect a seven-year-old to do. She was making noises and trying to talk literally since she was born and by age one her vocabulary was quite good. She was using full sentences almost as soon as she started to speak," he revealed.

Dr Hankins said Heidi was drawing princesses and animals aged 14 months - an age when most children can only mark the page.

And at 18 months the family found her using the computer to teach herself to read.

Heidi is a head taller than her classmates, and at 3ft 10in is closer to an average six year old.

The Hankins, from Winchester, Hampshire, also have a nine-year-old son, Isaac, who is a chorister at Winchester Cathedral.

"Heidi has really flourished quicker than other children - academically, artistically and physically, Dr Hankins said.

"We don't push Heidi at all. She has taken up everything herself and teaches herself.

"She is not precocious, she is just a little girl who likes her Barbies and Lego but then you will find her sitting down and reading a book," Dr Hankins said.

The average adult IQ score is 100 while a 'gifted' score is 130.

"Heidi's parents correctly identified that she shows great potential," John Stevenage, chief executive of British Mensa, added. (ANI)